Flow bodies as parts of an aircraft, a vehicle or of another apparatus subjected to a surrounding flow are often required to show aerodynamic characteristics that result in a substantially fully attached flow in a variety of flow conditions. For example, commercial aircrafts are designed for wide flow velocity and altitude ranges. In boundary conditions, such as during high lift flight, it is possible to use active flow control systems for preventing flow separation from an aircraft wing or other surfaces. In comparison to conventional surfaces, active flow control can lead to an increased lift by eliminating separations, while holding the angle of attack constant, or by delaying the stall of a particular surface to higher degrees of flow incidence, consequently increasing the lift as well. This is expedient and advantageous especially for wings of an aircraft, vertical or horizontal tail planes or other control surfaces attached to a part of an aircraft.
It is known to employ fluidic actuators for influencing the flow along a flow surface of a flow body. These fluidic actuators may be realized in such a way that they provide a pulsed ejection from openings in the flow surfaces. This ejection is able to delay separations to higher flow incident angles by introducing vortical structures, which convect downstream of the flow element, thus energizing the otherwise separated flow area. By optimizing the pulsation frequency, the duty cycle and the momentum injection through the openings according to the local flow phenomena, a highly efficient active flow control system can be created. Usually, these fluidic actuators utilize valves or other active flow influencing means for the provision of the pulsed ejection flow.
EP 2 650 213 A1 discloses a flow body having a surface and a leading edge having an active flow control system, wherein the active flow control system comprises a plurality of openings, at least one control pressure varying device and at least one fluidic actuator with an interaction chamber having an inlet connectable to an air source, at least two outlets and at least two control pressure ports. The openings are distributed along or parallel to the leading edge in a side-by-side relationship and extend through the surface. The control pressure varying device is connected to the at least two control pressure ports in a fluidic manner, wherein the control pressure varying device is adapted to bring about the flow of the fluid into a respective one of the outlets. Each of the outlets is connected to one individual opening of the plurality of openings.
In addition, other aspects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.